I am trying to pull the ball lock/spear out of this stubborn sanke keg, but can't for the life of my manage to pry the ring out. All other kegs have been a piece of cake, for some reason this one isn't going down without a fight. Any tips/tricks for getting this damn ring out so I can convert this final keg? the ring is wedged in such a way that I can't fit any blade/screwdriver/anything in the gap.